Properties of bulk matter describe how large collections of matter behave under force, pressure, heat or flow. These properties include elasticity, stress, strain, pressure, viscosity and surface tension.
Elasticity
The ability of a body to regain its original shape after deforming force is removed.
Viscosity
The internal resistance offered by a liquid to flow.
Surface Tension
The tendency of a liquid surface to behave like a stretched elastic membrane.
🌈 5W-1H + 1U
🔴 What: Bulk matter properties describe the behaviour of solids and fluids as a whole.
🟠 Why: They help explain stretching, compression, flow, pressure and liquid surface behaviour.
🟡 When: These properties are observed when materials are pulled, compressed, bent, heated or made to flow.
🟢 Where: They are used in bridges, machines, fluids, medical devices, construction and engineering.
🔵 Who: Students, scientists, engineers, architects and doctors use these concepts.
🟣 How: They are studied using quantities like stress, strain, pressure, viscosity and surface tension.
⚫ 1U: Bulk matter properties connect microscopic particle behaviour with large-scale material behaviour.
🔩 Elasticity, Stress and Strain
Animated Elastic Spring
The spring stretches under load and tries to return to its original length.
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Elasticity is the property by which a material regains its original shape after the deforming force is removed.
Stress = Force ÷ Area
Strain = Change in length ÷ Original length
Young’s Modulus = Stress ÷ Strain
Term
Meaning
Formula
Stress
Internal restoring force per unit area
Stress = F/A
Strain
Fractional change in dimension
Strain = ΔL/L
Young’s Modulus
Measure of stiffness of a material
Y = Stress/Strain
💧 Fluid Properties: Viscosity and Surface Tension
Surface Tension Demo
The liquid surface behaves like a stretched elastic sheet.
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Surface tension is the tendency of the liquid surface to minimize its area and behave like a stretched membrane.
Viscosity Demo
The ball falls faster in a less viscous liquid and slower in a more viscous liquid.
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Less viscous
More viscous
Viscosity is the resistance offered by a fluid to flow. Honey is more viscous than water.
Pressure in Fluids
Pressure in a fluid acts in all directions and increases with depth.
Viscosity
Viscosity controls how easily a liquid flows.
Surface Tension
Surface tension allows insects to walk on water and droplets to form spherical shapes.
🧮 Bulk Matter Calculators
Stress Calculator
Stress = Force ÷ Area
Strain Calculator
Strain = Change in length ÷ Original length
Young’s Modulus Calculator
Y = Stress ÷ Strain
✅ Properties of Bulk Matter Quiz
🧠 HOTS Questions
1. Why does a steel wire return to its original shape after stretching slightly?
Because steel is elastic within its elastic limit.
2. Why does honey flow slower than water?
Honey has greater viscosity, so it offers more resistance to flow.
3. Why do water droplets become nearly spherical?
Surface tension pulls the liquid surface inward and tries to minimize surface area.
4. Why are bridges designed after studying elasticity?
Engineers need to know how materials deform under load and whether they return to original shape safely.
5. Why does pressure increase with depth in a liquid?
At greater depth, there is more liquid above, so the weight of the liquid column is larger.
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